FI62879B - FAIRGREAKTIVT UPPTECKNINGSMATERIAL OCH FOERFARANDE FOER DESS FRAMSTAELLNING - Google Patents

Description

E3F * 1 W (11) KUU-UTUSJULKAI * U 0 - LJ utlAgonINOttKm ^ T 62 87 9 (51) Kv.fc.Vci.3 D 21 H 5/00 f B 41 H 5/12 ENGLISH— »FINLAND (» ) 7-2130. (M) HiluwlwMvlA — BlM> ti> frfn 03.07 * 78 "(23) AMwptlvt — CHtighM · *! O3.O7.78 (41) TullutfuNiMnl — MMt« IfcutNg 13.01.79 · * · »fVflKiritynlun AwaMw vtlfd ach 30 (32) (33) (31) hr * «* r« mHmm - * «fM priertt * 12.07.77

Federal Republic of Germany-Förbundsrepubliken

Germany (DE) P 2731 ^ 18.7- ^ 5 (71) Feldmiihle Aktiengesellschaft, Fritz-Vomfelde-Platz U, UOOO Dusseldorf-Oberkassel, Federal Republic of Germany Forbundarepubliken Germany (DE) (72) Kurt Riecke, Kempen, Ferdinand Land, Viereen The present invention relates to a tracer, in particular to a dye acceptor and in particular to a colorant to produce breakthroughs according to a color reaction method, the paper comprising a color acceptor layer which, together with the color formers, forms a color.

Labeling agents are known which contain a color acceptor layer which is sensitive to certain chemical compounds. When color acceptors come into contact with such first colorless compounds, so-called color formers, they form color. Known examples of such color acceptors are attapulgites or so-called acid clays. Commonly used color formers include chromogenic compounds such as crystal violet tylactone, malachite green lactone, benzoyl-leukomethylene blue, N-phenyl-leucuramine and the like. The color formed then depends primarily on the choice of the color formation component. Often not, however, the color intensity or consistency achieved is sufficient. As a result, attempts have already been made to further improve the color acceptor properties by adding metal salts. The known proposal comprises · adding water-soluble metal salts, e.g. zinc chloride, to the coating composition containing color-reactive pigments and binders. However, this measure does not achieve any significant improvements because the amount of metal salt required to improve the electron uptake of common mineral dye acceptors cannot be increased without adversely affecting the stability of the latex used as a binder for the coating composition, or without coagulating the latex.

These metal salts are present in the paper either as the salt itself or as metal hydroxides. Metal salts also settle in part in the lattice of common color acceptors composed of mineral dye-reactive pigments.

Also, the addition of water-soluble neutral salts to the paper material, as described in DE-A-14 71 717, provides only a small improvement in reactivity. These lead, manganese and cobalt salts, also known as driers of printing inks, have a dark color, especially the highest degrees of oxidation, and are therefore of limited use in white papers.

A subsequent proposal, described in the applicant's patent DT 26 01 865 * 5, thus comprises that by forming a zinc amine complex in the coating composition, the color-reactive properties can be further improved, higher amounts of zinc can be incorporated into the finished paper and coagulation of the latex can be avoided. In this case, the zinc chloride is converted into a soluble zinc amine complex with NH 4 OH in the preparation of the coating composition. This method can improve the color-reactive properties because higher amounts of zinc can be incorporated into the finished paper without the risk of latex coagulation due to the zinc compounds in the coating composition. However, the amounts of NH 2 OH required to convert the zinc chloride are so large that the diffuse load caused by the amounts of NH 4 released during the drying of the paper web cannot automatically be disregarded in industrial production.

The object of the present invention is to provide a label having improved properties and to avoid the drawbacks described above. In particular, the resistance of the color acceptor layer to aging is improved, which applies to both the aging of the print and the writability of the paper after aging, i.e. after prolonged storage of the unwritten paper. In particular, it is an object of the present invention to improve the rheology of paint paints compared to paint paints to which water-soluble metal salts have been added. Another object of the invention is to avoid the formation of an odor which occurs in connection with the above-described method of utilizing the zinc amine complex.

The present invention therefore relates to a label having color acceptor properties for the production of replicas and perforations containing color acceptors in a single layer, and characterized in that the label contains, in addition to color-reactive mineral pigments, water-insoluble or sparingly soluble ', NO 2 - and which are reaction products formed in an aqueous medium in the periodic table of elements II. one or more water-soluble salts of the side group metals and transition metals vanadium, iron, chromium, cobalt, manganese and nickel with time hydroxides. The invention also relates to a method for producing a coating composition.

These salts are likely to be suitable due to the fact that they can form a multilayer lattice and thus have a beneficial effect on the color development properties. The above-mentioned neutral salts described in DE-A-14 to 71 7 ^ 7 have only a single-layer lattice and not even a basic lead salt has a double-layer lattice. These salts are thus only able to improve the color reaction only moderately.

A very particularly preferred sparingly soluble basic metal salt is basic zinc chloride of the formula

ZnCl 2 [zn (OH) 2] 4-.

Such a zinc salt is formed by the reaction of zinc chloride with e.g. sodium or potassium hydroxide. It is essential in the reaction, on the one hand, that the reaction is carried out to such an extent that the basic metal salt formed is sufficiently sparingly soluble and, on the other hand, that the reaction is not carried out to such an extent that complete hydrolysis takes place. Only by considering these conditions will it be ensured that the Theology of Brush Dyes is not adversely affected with respect to the coagulation of latex caused by unbound metal ions and that optimal dye-reactive properties are achieved in the receiving layer. The preferred result is obtained when only 80% of the amount of time hydroxide required to precipitate pure metal hydroxide is added. t. . Λ 4 62879

Suitably, the precipitant is injected into an aqueous dispersion of mineral color-reactive pigments which already contains the metal salt in dissolved form, while vigorously stirring. In this way, the effect of the basic salts according to the invention can be enhanced by their precipitation on high color-reactive mineral color-reactive pigments, thus enhancing their effect.

In no case should the basic metal salts of the invention be mixed with a base of metallic compounds which are added to a slurry of color-reactive pigments or other color acceptors and binders and which dissolve in an aqueous slurry without precipitation, as in the case of the present invention. in the methods of the invention.

These compounds have the disadvantage already described above that their ions adversely affect the stability of the latex used in the coating composition. But also insoluble metal compounds, such as, for example, zinc oxide, which has also been proposed for use in improving the color intensity, do not give the positive result obtained by the present invention. Compounds of the latter type have no affinity for conventional mineral dye-reactive electron acceptors and are thus only of limited suitability for raising the electron acceptor potential of the dye acceptor layer.

The invention can be further improved by using an alkali salt of rosin acid in addition to alkali hydroxide as a co-solvent. The reaction products containing the metal salts of the invention and the resinate of the alkali metal hydroxide and rosin acid resin apparently improve the color conversion of the leuko compounds to the carrier oil of the color-forming microcapsules due to the improved oil solubility of the metal salt compounds.

Suitable precipitating components are both water-soluble alkali metal salts of pure rosin acids, such as, for example, abietic acid, and water-soluble alkali metal salts of rosin-acid-enhanced rosin admixtures with mixtures of rosin acid and acrylic acid, acrylic acid ester or maleic acid or maleic acid ester.

Known color-reactive clays can be used to prepare the label according to the invention. Preferably, electron acceptors with a high active surface area are used, such as, for example, montmorillonite clays containing a certain amount of Ke +++ ions inside the layer lattice, or alumina containing Al 2 O 2 obtained from aluminum trihydroxide in the form of alumina hydroxide or alumina At temperatures of 300 to 1000 ° C. At dewatering temperatures, a mixture of alumina hydroxide, alumina hydroxide and alumina in the ^ form is obtained with an annealing loss of 30-1% by weight. For optimal results, use a dewatering temperature of 610 to 710 ° C. At these temperatures, the EIA-converted alumina hydroxide has optimal theological properties with an annealing loss of about 4-10% by weight.

By yvA ^ O ^ is meant all thermodynamically unstable A ^ O ^ form and in the temperature range 300-100 ° C as formed in the dewatering of aluminum trihydroxides such as bayerite and especially hydrargillite, or alumina hydroxide in the form of boehmite which have not yet been stable above 1150 ° C.

By selecting the mixing components, the properties of the label can be influenced. Maximum light fastness is obtained by using pure clays, maximum resistance to aging by using a high proportion of V ^ A ^ O ^. With a suitable choice of mixing components, the properties can be changed in one way or another.

The use of iron-containing montmorillonite clays leads to a good color reaction, especially when benzoyl-leukomethylene blue is used as the color former, because this color former is converted into a stable colored compound due to oxidatively active iron ions. In the resulting clays containing only a small amount of iron, part of the basic salts can advantageously be formed from one or more metals which, by changing the oxidation state, preferably act as oxidation catalysts, such as, for example, copper.

A preferred composition of color acceptors contains 30-50% by weight of Y4 alumina, i.e. alumina hydroxide, optionally alumina hydroxide 70-50% by weight of color-reactive clay 2-12% by weight of basic zinc salt, calculated as zinc oxide 0.1- 2% by weight of copper compounds, calculated as copper II oxide from the total pigment content, all values naturally totaling 100%.

To prepare the label according to the invention, the procedure is as follows: 6 62879 To prepare the coating composition, a water-soluble metal salt is added to an aqueous slurry containing a dispersant of color-reactive pigments, and then a precipitant is added dropwise or by spraying while vigorously stirring. The amount of precipitant is thus measured to form a sparingly soluble or water-insoluble basic metal salt compound. As the precipitation continues, an increasingly thicker turbidity is formed which can be removed by adding about 1A moles of aluminum chloride based on one mole of soluble metal salt used.

Preferably, another dispersant in the form of a polycarboxylic acid salt is added to the ammonium salt solution, followed by the addition of a plastic binder, for example butadiene-styrene latex. To further reduce the viscosity, a small amount of the alkali salt of the polyelectrolyte can be added. However, the pH of the finished coating composition is then always below 7, as this value ensures that no excess alkali is present, while ensuring sufficient insolubility of the basic metal salt compounds combined with optimum reactivity with the color former used.

The finished coating paste can be applied to the chalk paper with conventional coating equipment. After drying and calendering, the sheet thus prepared can be used as the lower sheet of the breakthrough series.

The following examples illustrate the invention and other preferred embodiments without, however, limiting the invention to the examples presented.

In the examples, a reciprocating raw paper with a starch surface preparation and a weight of 41 g / m 2 on both sides is used as the coating substrate. The paint was applied unilaterally with 2 cloth brushes in an amount of 6-6.5 g / m and then dried in the usual manner.

The following experiments are used in the examples for evaluation: 1. The change in contrast between writers and paper after charging.

2. Changes in contrast between writing residues and paper after aging.

5. Receipt writability after thermal aging.

To perform the experiments, the test piece is written, for example, as the second breakthrough of a standard form set with the lowercase x of the typewriter in places using an impact force of 5, the receiving sheet being connected to a standard output sheet containing a KVL / NBLM combination. It is then exposed to daylight or artificial light or stored at 70 ° C and 75% relative humidity. From the measurement of whiteness before and after exposure, the change in contrast can be calculated from the following formula: (Wu - Vb) x 100 K (o / 0 ·)

Wu

Wu = whiteness of the unwritten specimen Wb = whiteness of the written specimen K = contrast of the written specimen in%.

The experimental results according to the examples are plotted and shown in Figures 1-4.

The figures show:

Figure 1 shows the effect of daylight on the contrast between the writing residues and the receiving paper.

Figure 2 shows the effect of artificial light on the contrast between the print and the receiving paper up to 1 MLxh.

Figure 3 shows the thermal aging of writers.

Figure 4 shows the thermal aging of the recipient and the writing therein.

Example 1

The polycarboxylic acid salt and the polyelectrolyte salt are dissolved in water as a dispersing aid. The acid-dissolved iron-containing montmorillonite is dispersed and then the iron-containing zinc chloride is dissolved therein. At the same time, with vigorous stirring, sodium hydroxide (Air-long-spray) is injected into it. After 30 minutes, the pH settles to about 6.6. The ammonium chloride solution mixed with the polycarboxylic acid salt is stirred and then styrene-butadiene latex is added as a binder.

To reduce the viscosity, a polyelectrolyte salt is also added.

300 parts by weight of water

Polycarboxylic acid salt 0,5 - "-

Polyelectrolyte alkali salt 0.1 - M -

Acid-monopolymonized mononitrile from Ee-p ^ t is 100 - "-

ZnCl 3 from 98% 16.47 - "- 8 62879

NaOH 30% to 26.33 parts by weight NH4Cl 25% 8 - "-

Polycarboxylic acid salt 1.5 - "-

Styrene-butadiene latex from 50% to 52.5 - "-

Alkali salt of polyelectrolyte from 40% 0.22 - "-

ZnO 100 act. pigment = 9.6% NaOH for Zn precipitation = 83.4 pH after Zn precipitation = 6.6 pH end = 6.6 cp 100 Upm = 80 By using more ferrous acid-dissolved montmorillonite in the combination according to the invention, good light fastness is obtained.

The thermal aging of a written sheet is good.

The rewritability of an outdated counter-data sheet is adversely affected by the absence of alumina in the form of ^.

Example 2

300 parts by weight of water

Polycarboxylic acid salt 0.5 - "- V ^ Al ^ Oj (10% annealing loss) 50 -" -

Fe-containing acid-dissolved montmorillonite 90 - "-

NaOH 30% 2,3 - "-

ZnCl 2, technical 98% 16.47 - "-

NaOH ’30% 24 -" - NH 2 CL 25% 8 - "-

Polycarboxylic acid salt 1.5 - "-

Styrene-butadiene latex from 50% to 52.5 - "-

Alkali salt of polyelectrolyte from 40% 0.32 - "-

ZnO / 100 act. pigment = 9.6% NaOH for Zn precipitation = 83.4 pH after Zn precipitation = 6.7 pH end - 6.6 cp (10 Gj, Upm = 60 9 62879

The incorporation of alumina in the Y 1 form slightly deteriorates the light fastness compared to Example 1.

The thermal aging of the written sheet is clearly better compared to Examples 3 and 4.

The rewritability of the obsolete recipient is good and better than in Example 1, and this is due to the alumina in the form used.

Example 3

Water 289 parts by weight

Polycarboxylic acid salt 0,5 - "- (10% loss on ignition) 70 -" -

Fe-containing acid-dissolved montmorillonite 30 - "- ΖηΟΐ £ techn. 98% 11,53 -" -

NaOH 50% 18.43 - "- NH 2 Cl 25% 5.6 -" -

Polycarboxylic acid salt 1.5 - "-

Styrene-butadiene latex from 50% to 52.5 - "-

Alkali salt of polyelectrolyte from 40% 0.32 - "-

Zn / 100 act. pigment = 6.75% NaOH for Zn precipitation = 83.4 pH after Zn precipitation = 6.7 pH end = 6.7 cp 100 Upm = 78

The high content of Y ^ -Al ^ O ^ reduces the light fastness. After good initial values, the values fall as a result of long-term loading.

A similar phenomenon occurs in the thermal aging of a written sheet.

The high content of Y 2 -A 2 O 3 gives excellent rewritability to the obsolete recipient, which is even better than Example 2.

Example 4 In this example, a non-inventive receiving sheet with a developer layer based only on acid-dissolved iron-containing montmorillonite is used. Acid-dissolved montmorillonite '; . ' Λ 10 62879 can be adjusted to pH 9.8 with soda water glass to improve activity in the dye.

Example 5

Water 289 parts by weight

Polycarboxylic acid salt 0,5 - "-

Fe-containing acid-dissolved montmorillonite 100 - "-

ZnCl2 technical 98% 11.53 - "- N'aOH 30% 18.43 -" - NH4Cl 25% 5.6 - "-

Polycarboxylic acid salt 1.5 - "-

Styrene-butadiene latex from 50% to 52.5 - "-

40% alkali salt of polyelectrolyte 0.32 '- "-

ZnO '/ 100 act. pigment = 6.75% NaOH for Zn precipitation = 83.4 pH after Zn precipitation = 6.6 pH end = 6.7 cp 100 Upm = 75

Example 5 behaves in the same way as Example 1 in terms of lightfastness.

Its handwriting stability seems to be slightly better than Example 1.

Examples 6 and 7 illustrate the addition of copper sulfate as an oxidation catalyst to the active pigment composition of ferrous montmorillonite and vf = -Al 2 O 2.

In Example 7, precipitation also takes place with resin soap.

Example 6

291 parts by weight of water

Polycarboxylic acid salt 0,5 - "- Y ^ A1205 (10% loss on ignition) 70 -" -

CuSO 2 .5H 2 O 20% 10.2 - "-

Fe-containing acid-dissolved montmorillonite 30 - "-

NaOH 30% 2.18 - "- ^ nÖl2 technical 98% 11.55 -" -

NaOH from 30% to 17.3 - "- 11 62879 NH 2 Cl from 25% to 8 parts by weight

Polycarboxylic acid salt 1.5 - "-

Styrene-butadiene latex from 50% to 52.5 - "-

Alkali salt of polyelectrolyte from 40% 0.32 - "-

ZnO / 100 act. pigment = 6.75% NaOH for precipitation of Me ++ = 80 pH after precipitation of Me ++ = 6.8 end of pH = 6.7 cp 100 Upm = 40

CuO / 100 part γ ^ Α ^ Ο ^ = 0.95

CuSO 4 is adsorbed onto alumina and then converted.

Example 7

291 parts by weight of water

Polycarboxylic acid salt 0,5 - "-

Alkali salt of polyelectrolyte 0.1 - "- non-ionogenic antifoam 0.2 -" - spAl20j 10% annealing loss 70 - "-

CuSO 4 H 2 O 20% 10.02 - "-

Resin soap from 30% (0.207 6 NaOH / 1 g Atro resin) 8.44 - "-

Fe-containing acid-dissolved montmorillonite 30 - "-

ZnCl2 technical 98% 11.53 - "-

Resin soap from 30% 17 - "-

NaOH 30% 18.43 - "- NH 2 Cl 25% 5.6 -" -

Polycarboxylic acid salt 1,5 - "- non-ionic defoamer 0.5 -" -

Styrene-butadiene latex from 50% to 52.5 - "-

Alkali salt of polyelectrolyte from 40% 0.3 - "-

ZnO / 100 act. pigment = 6.75

NaOH to precipitate Me ++ = 80% Zn ZnCl 2 as Q 2 (OH) 2] ^ = 60 after precipitation pH = 6.8 · 5 '.1 V! pH end = 6.8 cp 100 Upm = 100

CuO calculated on 100 parts of Y 2 Al 2 O 2 = 0.93

Claims (21)

12 62879 A tracer, in particular a color reaction paper having color acceptor properties for producing copies and punctures according to a color reaction method comprising a color acceptor layer which together with color formers forms a color, characterized in that the tracer contains halogens acetate, NO 2 - and which are reaction products formed in an aqueous medium according to the Periodic Table of the Elements II. of one or more water-soluble salts of the side group metals and the transition metals vanadium, iron, chromium, cobalt, manganese and nickel with alkali hydroxides. Labeling agent according to Claim 1, characterized in that it contains, as a water-insoluble basic metal salt, a zinc salt of the formula ZnCl 2 [zn (OH) 2] 4. Labeling agent according to Claim 1, characterized in that the sparingly soluble or water-insoluble basic metal salt is the reaction product of a water-soluble metal salt with an alkali metal hydroxide and an alkali salt of rosin acid. Labeling agent according to Claim 3, characterized in that the rosin acid is polybasic and can also be partially esterified. Labeling agent according to Claims 3 and 4, characterized in that the polybasic rosin acid is a rosin resin reinforced with maleic acid. Labeling agent according to Claims 3 to 5, characterized in that the resin acid is a rosin resin reinforced with acrylic acid. Labeling agent according to Claims 1 to 6, characterized in that it contains, as color acceptors, color-reactive clays and / or alumina hydroxide or alumina hydroxide having alumina in the Y 1 form. Labeling agent according to Claims 1 to 7, characterized in that it contains acid-dissolved iron-containing montmorillonite as a color-reactive clay. 15 62879 Labeling agent according to Claims 1 to 8, characterized in that it contains alumina hydroxide or alumina trihydroxide with alumina in the Y 1 form and an annealing loss of 30 to 1% by weight. Labeling agent according to Claims 1 to 9, characterized in that the color acceptor is a mixture of T-Al 2 O 3 and ferrous montmorillonite in a weight ratio of 90:10 to 10:90. Labeling agent according to Claims 1 to 10, characterized in that the total amount of basic metal salts is 2 to 30% by weight, calculated as metal oxides, of the total number of color acceptors. Labeling agent according to Claims 1 to 10, characterized in that the total amount of basic metal salts is preferably 5 to 10% by weight, calculated as metal oxides, of the total amount of color acceptors. Labeling agent according to Claims 1 to 11, characterized in that the basic metal salts are doped in a finely divided form on conventional color acceptors. Labeling agent according to Claims 1 to 11 and 13, characterized in that it further contains 0.1 to 10% by weight of metal compounds acting as oxidation catalysts, calculated as metal oxides, based on the total amount of color-reactive pigments. · Labeling agent according to Claims 1-11 and 13-14, characterized in that the color acceptors additionally contain copper compounds. Process for preparing a coating composition for a tracer according to one of Claims 1 to 15, characterized in that cobalt of metals of the group II of the Periodic Table of the Elements or of vanadium, such as chromium, cobalt, chromium, and one or more water-soluble salts of iron which form sparingly soluble or insoluble basic salts with alkali hydroxides and rosin acids, and alkali hydroxide and resin soap or a simple solution of alkali hydroxide containing an alkali metal, -attate ”, NO 2 and resinate, that an aqueous solution of the ammonium salt is mixed into this mixture and then a plastic dispersion is added as a binder, whereby the pH of the coating composition is less than 7 · 14 62879 A method for preparing a coating composition for a tracer according to claim 16, characterized in that a polycarboxylic acid salt is added as a dispersing aid. Process for the preparation of a coating composition for a tracer according to Claim 16 or 17, characterized in that an alkali salt of a polyelectrolyte is added as a dispersing aid. Process for preparing a coating composition for a tracer according to one of Claims 16 to 18, characterized in that ammonium chloride is used as the ammonium salt. Process for preparing a coating composition for a tracer according to one of Claims 16 to 19, characterized in that an aqueous slurry containing a dispersant of mineral color-reactive pigments and a water-soluble salt is vigorously agitated and the precipitant is sprayed into this slurry.